Annealing Time Effect on the Structural, Optical, and Electrical Characteristics of Titanium Dioxide Thin Films

Using the sol-gel spin coating method, TiO2 thin films are fabricated and annealed at 500℃ for different annealing times, i.e., 1 hour, 2 hours, 3 hours, and 4 hours. Annealing time is one of the parameters that influence the properties of thin films. This work investigates the effect of annealing time on the structural, optical, and electrical properties of TiO2 films. All the films have a single anatase crystalline phase. The crystallite size increases with annealing time from 1 hour to 2 hours and then decreases. A decrease in band gap is observed due to an increase in grain size. The film annealed for 4 hours has the least resistivity.